/*
 * Copyright (c) 2011 Imre Fazekas.
 * All rights reserved.
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 *
 * Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 * Neither the name of the Brillien nor the names of its
 * terms and concepts may be used to endorse or promote products derived from this
 * software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

package com.vii.brillien.core.component;

import com.vii.brillien.ignition.transport.BrillienCommunication;
import com.vii.brillien.kernel.BrillienException;
import com.vii.brillien.kernel.axiom.atomic.Context;
import com.vii.brillien.kernel.axiom.atomic.Presence;
import com.vii.brillien.kernel.axiom.atomic.Unit;
import com.vii.brillien.kernel.axiom.atomic.shaper.Filter;
import com.vii.brillien.kernel.axiom.atomic.shaper.Shifter;

import java.util.concurrent.ConcurrentHashMap;

/**
 * Reference implementation of term Context defined by the powerobject model
 */
public class AbstractContext <P extends Presence, R> extends SuperUnit<P,R> implements Context<P,BrillienCommunication,R> {

    /**
     * Sharings available all Presences of the Flow, regarded as a Context
     */
    protected ConcurrentHashMap                     sharings;
    protected ConcurrentHashMap<Filter, Shifter>    exceptionLevels;
    

    @Override
    public <T> void registerSharing(Presence p, Object key, T object) {
        sharings.put( key, object );
    }

    @Override
    public void removeSharing( Presence p, Object key ){
        sharings.remove( key );    
    }

    @Override
    public boolean hasSharing(Presence p, Object key) {
        return getSharing( p, key ) != null;
    }

    @Override
    public <S> S getSharing(Object key){
        return this.<S>getSharing( this, key );
    }

    @Override
    public <S> S getSharing(Presence p, Object key) {
        if( sharings.containsKey( key ) )
            return (S)sharings.get( key );

        for( Unit u : superUnits )
            if( u instanceof Context ){
                Context c = (Context)u;
                if( c.hasSharing( p, key ) )
                    return (S)c.getSharing( p, key );
            }

        return null;
    }

    @Override
    public void addExceptionLeveling( Filter f, Shifter s ){
        exceptionLevels.put( f, s );
    }

    @Override
    public void removeExceptionLeveling( Filter f ){
        exceptionLevels.remove( f );
    }

    @Override
    public void clearExceptionLeveling( ){
        exceptionLevels.clear();
    }

    @Override
    public Shifter getShifter( BrillienException be ){
        for (Filter filter : exceptionLevels.keySet())
            if( filter.interestedIn( be ) )
                return exceptionLevels.get( filter );

        for( Unit u : superUnits )
            if( u instanceof Context ){
                Context c = (Context)u;
                Shifter sh = getShifter( be );
                if( sh != null )
                    return sh;
            }

        return null;
    }

    @Override
    public BrillienException levelException( BrillienException be ){
        Shifter sh = getShifter( be );
        return sh == null ? be : sh.transform( be );
    }

    @Override
    public void reset(){
        super.reset();

        sharings = new ConcurrentHashMap();

        exceptionLevels = new ConcurrentHashMap<Filter, Shifter>();    

        registerSharing( this, this.getName(), this );
    }
    
}
